Abstract: A chain net comprises a plurality of warp strands (1.1) with mutually equal links (1.2) which at intersections lock round links (1.5) of weft strands (1.4) having mutually equal links. The links of the warp strands have dimensions such that they first allow the insertion of weft strands and, after plastic or elastic deformation, lock links of the weft strands. The plastic deformation is provided by elongating the warp strands. The elastic deformation is provided by the warp strand links being first expanded to allow the insertion of weft strands, after which the warp links are elastically re-deformed for locking round weft links.

Abstract: A machine for electrical resistance welding of chain links has upsetting bars (10) which are engaged against the arcuate ends of a chain link (1). On either side of the welding zone the legs of a link are gripped by pairs of electrodes (12) attached to the ends of a two-armed clamp (14). The arms (13) of the clamp are mounted for pivoting in a plane at right angles to the chain link, and also about an axis in this plane extending at right angles to the upsetting direction and passing through journalling head (20) attached to the end of a piston rod (21) of a counteraction cylinder (20). The ends remote from the electrode jaws (12) of the clamp arms (13) are acted on by an operation cylinder (30) which, via a link system (16, 16), gives the clamp a gripping movement about the link leg. The cylinder (20) with cylinder (30) and the clamp (14) commonly form a welding head which is pivotable about an axis (z-- z) at right angles to the upsetting direction.